Pictures: Wildfires rage in CaliforniaPublished10 October 2017Image source, ReutersImage caption, Fierce fires are raging across nine counties in the US state of California.Image source, EPAImage caption, The fire service is battling 15 separate fires from the air and on the ground.Image source, ReutersImage caption, A state of emergency was declared in northern areas of California, including Napa, Sonoma and Yuba. Around 20,000 people have fled their homes.Image source, ReutersImage caption, This helicopter has been dropping water on the fire in strong winds in the city of Orange in southern California.Image source, AFPImage caption, Residents watch efforts to put out the fire on from a hill.Image source, AFPImage caption, These horses are being evacuated from their fields to keep them safe as strong winds blow smoke and fire in Orange.Image source, ReutersImage caption, Planes are being used to drop this red powder over the wildfires. It is supposed to dampen down the flames and stop the fire spreading.Image source, Getty ImagesImage caption, It's not yet known how the fires started but high winds and hot, dry weather have made them spread quickly.Image source, AFPImage caption, The glow of the wildfire in Napa in northern California lights up the night sky.